Rose J K, Yanofsky C
Proc Natl Acad Sci U S A. 1974 Aug;71(8):3134-8. doi: 10.1073/pnas.71.8.3134.
Transcription studies in vitro on repression of the tryptophan operon of Escherichia coli show that partially purified trp repressor binds specifically to DNA containing the trp operator with a repressor-operator dissociation constant of about 0.2 nM in 0.12 M salt at 37 degrees , a value consistent with the extent of trp operon regulation in vivo. The half-life of the trp repressor-trp operator complex is less than 2 min in vitro in 0.12 M salt.
对大肠杆菌色氨酸操纵子阻遏作用的体外转录研究表明,部分纯化的色氨酸阻遏物能特异性地结合含有色氨酸操纵基因的DNA,在37℃、0.12M盐浓度下,阻遏物与操纵基因的解离常数约为0.2 nM,这一数值与色氨酸操纵子在体内的调控程度相符。在0.12M盐浓度的体外环境中,色氨酸阻遏物 - 色氨酸操纵基因复合物的半衰期不到2分钟。